Space cooling represents 11% of energy consumption in New York City buildings larger than 50,000 ft2. Most of these systems are powered by electricity, but some of the larger buildings also use absorption chillers powered by natural gas or district steam. Only space heating, plug loads and lighting consume more energy than space cooling in NYC.
Many buildings in New York City still have very inefficient lighting. In 2016, the Urban Green Council determined that 40% of multifamily buildings and 25% of office buildings above 50,000 ft2 are illuminated mostly by incandescent bulbs and first-generation fluorescent lamps. In addition to being inefficient themselves, these lighting systems are characterized by a high heat output, which burdens air conditioning equipment and causes an increase in space cooling expenses. Lighting loads represent the third-largest energy use in NYC buildings, accounting for 13% of overall consumption. In the case of office buildings, this value is increased to 18% because lighting use follows work hours.
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Since 2009, the New York City government has carried out an ongoing effort to gather relevant data on how energy is being consumed by NYC buildings. An attempt to audit every single property would be unfeasible in terms of both cost and time, so efforts have focused on the buildings that consume the most energy.
To control energy consumption effectively it must first be measured, since that is the only way to establish energy efficiency baselines and targets. However, knowing how much energy is consumed is not enough - targeted measures can only be implemented with a detailed breakdown of energy consumption.
According to the National Electrical Manufacturers Association (NEMA), electric motors account for nearly 40% of total electricity consumption in the US, especially in the industrial and commercial sectors. Improving motor efficiency throughout the country represents a significant opportunity to save energy, so NEMA launched the first version of its Premium Efficiency standard for motors in 2001.
New York City has some of the most ambitious renewable energy and emissions reduction targets in the USA. The city aims to reduce its emissions by 80% before the year 2050, with respect to the levels measured in 2005. This reduction is equivalent to 43 million metric tons of greenhouse gases per year, and the emissions reduction potential in buildings alone is estimated to be 25 million metric tons of GHG, which represents nearly 60% of the 2050 goal.
Electronically commutated motors (ECMs) can achieve significant energy savings in applications where fractional horsepower is required. Although NEMA Premium Efficiency motors with variable-frequency drives provide the most efficient solution to drive equipment above 1 hp, induction motors are outclassed by ECMs as the rated horsepower is reduced.
When Hurricane Sandy made landfall in NYC in 2012, the resulting damage cost the city around $19 billion. The storm left around 20% of New Yorkers without power, completely flooded the subway system and even shut down the stock exchange for two days. In addition, around 20,000 buildings were damaged and there were more than 50 casualties.
Energy and electricity are complex technical topics, and for the general public it can be hard to tell which products are energy efficient. The US Department of Energy (DOE) has been creating and enforcing standards since 1979 to ensure that appliances and equipment provide value for customers. This has been one of the most effective energy efficiency policies ever implemented by the US, yielding billions of dollars in energy savings each year.
New York has a statewide Clean Energy Standard, which establishes that 50% of the state’s energy must be generated from renewable sources by the year 2030. However, there is a key challenge involved: although solar photovoltaic systems and wind turbines deliver clean and affordable electricity, their output cannot be adjusted to follow consumption. Therefore, utility companies must now manage variability in both generation and consumption.